Oxygen Reserve Index and Arterial Partial Pressure of Oxygen: Relationship in Open Heart Surgery.

Background: Mild to moderate hyperoxia is potentially beneficial to patients undergoing open heart surgery. Oxygen Reserve Index (ORI) is a novel parameter that correlates to arterial oxygen tension (PaO) in the hyperoxic range. This prospective study aimed to assess whether the relationship between ORI and PaO remains intact in the setting of open-heart surgery.